Oil well pump and the like



May 23 1944- R. L. CHENAULT 2,349,649

OIL WELL PUMP AND THE LIKE Filed Feb. 21, V1941 2 sheets-sheet 1 mi W ,W7 m@ 6 7 o 5 2 w J2 2 2 ,M m 2 r P w 3 i1 3 a 2 E 7 l 3% 9 www 2 z// W f. q 2 y i 54 g 2 2 2 f 7 m m d d j 73. 6 5 Q L@ m Zw n f May 23, 1944 R. L.. CHENAULT v2,349,649

OIL WELL PUMP AND THE LIKE Filed Feb. 2l, 1941 2 Sheets-Sheet 2 7 `I 7a r ,7W zi Q@ q2 2@ i 66 Q /4/60 7g MEL 7] x J k l q? 55%@ 67 v 1 i /56 /\70 1 55 H 7/ f f @AS N l 7\ 5 LIQUID mmm; A YV CHAMBRR i E 76 w255g; Q6

f I f f5 Y I fs j@ g5 @As muil* A. f /CHAMBER 101 f* 8O gs 17 K 8] /j f O e/ 2Q L 7- 93 66 14 gime/whom 6 ELC/m4', ]2 /'V Q5 y Y- N VENT To wfLL GAS EXHAUST 3343 V27 I L-. f @Hm/@ER 1o@ www Patented May 23, 1944 OIL yWELL PUMP AND THE LIKE Roy L. Chenault, Oakmont, Pa., assigner to Gull Research & Development Company, Pittsburgh, Pa., 'a corporation of Delaware Application February 21, 1941, Serial No. 380,043

(Cl. S-231) 12 Claims.

This invention or discovery relates to oil well pumps and the like; and it comprises in a pump for pneumatically lifting liquids in successive slugs, a displacement chamber adapted to be positioned in the liquid in a well, said chamber being provided with a valve seat and an axially f movable valve for the seat for controlling venting of the chamber of entrapped gas into the well, a source of gaseous iluid under pressure, a second valve seat and axially movable valve for the seat for controlling the delivery of gaseous fluid from said source to said chamber, a vertically reciprocable eduction tube in communication with the lower part of the chamber and extending therefrom to the top of the well, and means connecting said eduction tube with said valve for operation of the same in accordance with the reciprocation of the eduction tube whereby when the eduction tube is moved in one direction gaseous pressureuid is admitted to the displacement chamber and when the tube is moved in the other direction the displacement cli/amber is vented into the well; all as more fully hereinafter set forth 3nd,' as claimed.

The general type of rpump of which this lnvention is an improvement is disclosed in my prior Patents 1,890,720, 2,059,508 and 2,083,687 and consists briefly, of spaced, substantially concentric outer and inner strings of tubing which extend down into the well and terminate in a displacement chamber positioned in the liquid in the well, and an eduction tube, respectively. Gas under pressure from a, suitable source at the top of the well is directed into the well through the space between the tubes and is distributed by means of a piston valve, actuated by reciprocation of the inner string of tubing, to the displacement chamber or to the eduction tube, as the case may be, for raising the liquid to the top of the well.

The present invention is directed to improvements in this type of pump, with a view to simplification of structure and prolongation of the life of the relatively moving valve parts thereof.

It is an object of the present invention to provide a Slugger type gas lift pump in which the member reciprocated to actuate the valves is constructed of two or more sections in interlocking valvular engagement.

A further objectof the present invention is the provision of a pump in which ground seat, metallic valves, advantageously of the poppet or lift type, are used in contradistinction to piston valves.

A still further object of the present invention is the provision of a slugger type of gas lift pump that is simple in design and construction, inexpensive of manufacture, easy to install and operate and which may be used for long periods oi time without the necessity of -repair due to wear.

These and-other objects are accomplished by the present invention as will be apparent from the following description and accompanying drawings wherein Fig. 1 is a view partly in vertical longitudinal section of the complete pump assembly including thelifting cylinder at the top for reciproeating the inner tube string,

Fig. 2 is an enlarged, detail, vertical, sectional view of the lifting cylinder and Figs. 2a and 2b are enlarged detail, vertical, sectional views of the pump valve assembly indicated in Fig. 1 by the lines 2a-2a and 2b-2b respectively.

Referring to the drawings wherein like numerals indicate correspnding parts thror hout the several views, fthe complete pump assembly shown in Fig. 1 consists of a lifting cylinder 5 supported on top of an outer tube string 6 by means of a Tpipe coupling member 1. The outer tube string is supported in the .well at the top through engagement with the casing head 8 of the well and is provided along its length with working barrels 9 and I0 respectively, positioned above and below a displacement chamber Il which is adapted to be submerged in liquid at the bottom of the well. Secured to the lower end of the outer tube string, as at I 2, is the usual well screen and mud anchor not shown. The inner tube ,string illustrated diagrammatically in Fig. 1, consists of upper and lower sections of tubing i3 and I4 respectively, which are connected together by interlocking sliding engagement with a coupling member indicated generally by the numeral I5. The inner tube string is adapted to be reciprocated vertically in the outer tube string by connection of the upper end of the.

upper section with a piston in the lifting cylinder in a manner about to be described. The lower section of the inner tube string extends through the displacement chamber and is provided with piston packing rings I 6 and I1 respectively where it passes through the working barrels 9 and I0. The lower end of the section is open and terminates at a point immediately below piston packing I'I. Pipe IB, which connects with the horizontal stem portion of the T coupling is provided for delivering gaseous fluid under pressure from a suitable source, not shown, to the space between the inner and outer tubes.

Referring vmore specifically to Fig. 2, lifting` cylinder 5 is provided with upper and lower cylinder' heads I9 and 20, respectively, and a piston 2I. The cylinder is spaced directly above T coupling l, in axial alignment with the inner tube string, on hollow standards 22 which are positioned between the lower cylinder head and a flanged stuffing box 23 secured to the coupling member by being in reduced screw threaded engagement therewith. Stud bolts 24 passing through the iange of the stufng box and through the hollow standards threadedly engage the lower cylinder head at points about its periphery and secure it to the outer tube string. The lower cylinder head is preferably secured to the cylinder by welding as at 25 and is provided exteriorly with a stuing box 26 through which the upper end of the inner tube string is passed. Interiorly, the lower cylinder head is provided with a number of spacing and cushioning elements 2l for limiting the downward travel of the piston. The upper cylinder head is bolted to a flange 26 on the upper end of the cylinder and is provided with a centrally disposed guide bearing 29 adapted to receive a hollow piston rod 30 attached to the piston and extending out through the top of the cylinder.

The piston consists of a relatively thick, closetting disk shaped member provided with a central opening through which the upper section of the inner tube string is adapted to pass. A packing gland 3l is provided in the opening for lorming a sealed, slidable connection between the piston and the outside walls of the inner tube string at this point. Packing material is retained in the gland by means of a relatively heavy, hanged follower or cover member 32 secured to the top of the piston by means of bolts 33. The piston is also provided with a packing gland 34 about its periphery for forming a sealed, sliding engagement with the interior walls of the cylinder. Suitable packing material is held in this annular piston packing gland by means of retaining ring 35 secured to the top of the piston by means of bolts 36.

Hollow piston rod 30 hereinbefore referred to is attached to the piston as by welding 31 to the member 32. As shown, the upper section I3 of the inner tube string passes from the well through T coupling 1, packing glands 23 and 26 of the lift cylinder assembly, packing gland 3| in the piston and hollow piston rod 30 to a point a short distance above the end of the piston rod where it is threaded as at 38 for reception of a nut 39 adapted for abutting engagement with the upper end of the piston rod. As shown, the threaded end 38 of the inner tube string ls adapted to extend a suitable distance above the nut 39. The purpose of this is to permit attachment of piping for conducting the liquid pumped away from the well to a reservoir or other point of use. Proper positioning of the inner tube string relative to the piston in the lift cylinder is obtained by adjustment of nut 39 along the end of the tube string. The piston is moved from the bottom to the top of the cylinder by admission of fluid pressure through a pipe 40 (Fig. 1) at a point beneath the piston and is lowered by the weight of the inner tube string acting through the piston rod when the huid pressure beneath the piston is released. For this purpose pipe 40 is provided with a threeway valve, not shown. Pipe 40 and the valve therein connect with a source of uid pressure and with a timing device respectively, also not shown.

Referring more specically to Figs. 2a and 2b. the displacement chamber I I is formed in two or more parts threaded together as at 4I and provided with reduced ends 42 and 43, respectively. The upper end 42 is provided adjacent its top with internal screw thread for connection with the working barrel 9, as shown, and is provided at .its bottom, on a shoulder formed where it merges with the displacement chamber, with a removable upwardly turned valve seat 44, which separates the displacement chamber from a gas exhaust chamber IUI] thereabove, which in turn is separated from a gas inlet chamber IUI by packing I6. Intermediate the valve seat 44 and the lower end of working barrel 9 is a vent or exhaust port 45 in open communication with the uid in the Well. The lower end 43 of the displacement chamber is connected to working barrel I0 by means of pipe coupling 46. Coupling I2 joins the well screen and mud anchor, not shown, with the end of barrel I0 as previously described.

The inner tube string, as stated, consists of upper` and lower sections of tubing I3 and I4 respectively, connected together by interlocking, sliding, telescopic engagement with the coupling I5 (Fig. 1). This coupling consists of a pipe nipple 4l connecting upper and lower outer sleeve members 48 and 49, respectively. Upper sleeve 48 is secured to the nipple through threaded connection with pipe coupling 50, while lower sleeve 49 is counterbored as at 5I where it threads on the nipple and receives a ball, check valve seat 52.' Valve seat 52 is clamped in the counterbore by the end of the nipple when the sleeve is screwed thereon, as shown. A pin 53, in the nipple forms a cage with the valve seat for retaining the ball valve 54. Sleeve 48 is provided adjacent its top end with a reduced opening formed by an annular, internal shoulder 55 immediately above which is a stuffing box 56, packing nut 51 and packing ring 51A. An inner sleeve 58, which is provided with an external collar 58 on its lower end adapted for engagement with the internal flange 55 on the outer sleeve when the sleeves are in extended position, extends through the reduced opening formed by the flange and through the stuffing box and is connected at its upper end to the lower end of the upper section of tubing by means of pipe coupling 60.

Valve port 6I is provided in the inner sleeve for establishing communication between interior of the upper tube string and the space between the inner and outer tube strings when the sleeves are extended. The port is closed when the sleeves are collapsed or telescoped by reason of its being carried downwardly into the stufllng box.

Lower outer sleeve 49 is provided internally at its bottom end with a removable, upturned annular valve seat 62 adapted for engagement with valve closure means provided adjacent the top end of lower section I4 of the inner tube string. For this purpose the top end of the lower section of the inner tube string is slidably disposed within the outer sleeve and is provided with an external annular shoulder 63 which has a ground face on 4its lower side adapted to engage the internal up turned valve seat on the sleeve when the parts are in extended position. Radial ports 64 are provided in the top end of the lower section of the inner tube string in open communication with the interior of the sleeve 49.

As shown, section I4 of the inner tube string extends from the outer sleeve 49 downwardly through working barrel 9, displacement chamber II and working barrel I0.

lowermost position. In the displacement charnber, the inner tube is provided with ports 68 in open communication with the top of the chamber and ls interrupted for a portion of its length by a coupling member 69. .,oupling 69 is provided with a reduced bore 18 adapted to slidably receive the lower end of eduction tube 1| the upper end of which is threaded with the counterbore 5I of the sleeve 49. An annular cylindrical space 12 is provided between the eduction tube and tube I4, by reason of the tubes being concentrically arranged and the eduction tube being of smaller diameter than the inside diameter of tube I4, but the space between the tubes is sealed at the coupling 69 by means of packing material 13 clamped in a counterbore 14 in the upper end of themember where it threadedly connects with tube I4. Continuing through the displacement chamber tube I4 is provided with a valve seat 15 adapted to receive a ball valve 16. This valve corresponds to the usual well pump standing valve with the exception that the present valve is carried by the inner tube string and is removable as a unit therewith. A radially extending pin 11 in tube I4 above the valve limits the upward movement of the ball 16 to that necessary to secure complete opening of the valve. vided with ports 18 a short distance above the valve in open `communication with the lower end of the interior of the displacement chamber. Valve seat is supported in tube I4 by being clamped against an inner annular shoulder 19 by an assembly supporting the lower packing piston I1. This assembly consists of a short length of tubing 80 in threaded connection with the end of tube I4 and provided with an annular shoulder 8l at a point in its length adapted for reciprocation in the working cylinder or barrel I0. The

piston packing material I1, which consists of prel or sleeve 83 threaded on the end of the tube.

In order that the inner tube string may be lifted out of the well independently of the outer tube string, the inside diameter of working barrel I0 is made slightly less than the diameter of the opening through valve seat 44. Thus not only is valve 15 removable as a unit with the inner tube string, but the force resulting from iiuid pressure in the displacement chamber tending to raise tube 66 and open the exhaust valve is opposed by the counteracting force resulting from pressure of the fluid in the chamber on piston I1 and valve members 15 and 16.

The pump is applied to an oil well by lowering the outer tube string with the displacement chamber attached thereto into the well through the well casing until the displacement chamber is submerged in the oil in the well at the desired producing level. The inner string of tubing is then lowered into the well until sleeve 66 on the The inner tube is reduced in external diameter where it passes' lower section I4 is seated on valve seat 44. Continued lowering of the inner tube string results in sleeve 49 of the coupling I5 sliding downwardly over thev top end of the lower section, thus opening the valve formed by the members 62 and 63. Coupling I5 will continue to move downwardly until it is stopped by contact of the top end of the lower section I4 with the top inner wall of the sleeve 49. At this time both the lower section I4 of the inner tube string and the coupling member I5 will be supported against further downward movement by the valve seat 44 on the outer-tube string, but the top portion I3 of the inner tube string is still free to move downward by reason, of the member 58 sliding within the top outer sleeve 48 of coupling I5. upper section is permitted to move downwardly with respect to coupling I5 only so farv as is necessary to close ports 6I in member 58. This is accomplished by adjustment of the nut 39 on the top end of the upper section to raise or lower the tube string the required amount with respect to the piston 2| in lift cylinder 5. 'Ihus tube sections I3 land I4 are joined for mechanical lost motion through the valvular, telescopic lengagement they have with coupling I5.,

In this position oil in the well may enter the pump through the well screen attached to the outer tube string at I2 and seek its own level i past check valves 16 and 54 inthe inner tube string depending on the level of the oil in the well.

the inner tube string. In starting operation' of the pump, with the parts in lowered position, the inner tube string is connected at 33 with a short length of flexible pipe to a pipe line for delivery of the oil discharged by the pump to the point of use or storage and gas under pressure is admitted to the space between theinner and outer stages of tubing through the pipe I8 connected tothe T 1. At this time ports 6I and valve port 44 will be closed while valve port 62 will be open. The gas then travels downwardly between the strings of tubing to the packing piston I6 in barrel 9 and then upwardly through open valve port 62 in the lower sleeve 49. Ports 64 in the top end of the lower string of vtubing I4 being open Aat all times the gas will then flow downwardly Ilo through passage 12 between the eduction tube 1I and the lower string of tubing and be discharged into the displacement chamber II through the ports B8.

If in starting the available gas pressure is not suflicient to lift the head of oil accumulated in the inner tube string, the upper section of the inner tube is raised by admitting gas under pressure through pipe into lift cylinder 5 below piston 2l. The inner tube string may be raised only sumciently to open ports II and admit the gas directly into the inner tube at a point cons'derably above the displacement chamber. At this point the head of oil is less and the pressure of the gas is suilicient to lift the oil to the top of the Well. The upper'section of the inner tube string is then lowered by release of the gas pressure from below piston 2| whereupon the oil remaining in the displacement chamber is forced v into the inner tube string through ports 18, closlng check valve 16 and passes upwardly past check valve 5,4 into the upper section. At this time the inner tube string is lifted to open ports 5I and valve port 44 and close valve port 62. Gas then entering the inner tube string through ports 6I will lift the oil to the top of the well.

However, the

At the same time the displacement chamv ber I I is lled with oil through the ports 18 in During this time the gas in the displacement chamber is released into the well casing through open valve port 44 and ports 45, and fresh oil from the well enters the chamber to ll it through the open end of the lower section of the inner tube string past check valve 16 and through ports 18 as before. When the `displacement chamber becomes filled with oil the inner tube string is lowered to its lowest position closing valve ports u and 6I and opening valve port 62, thus completing the cycle of operation of the pump.

In use, the three-way valve (not shown) in pipe 40 may be connected to an automatic timing device to cause automatic lifting and lowering of the inner tube string with the emptying and filling of the displacement chamber.

The pump as described is particularly simple in design and construction and is eillcient and long lived in operation. Valve ports 62 and 44 together with their closure members form valves of the poppet type which may be made of hard alloy metal and ground to a close t. Sleeve valve 6I is also long lived for the reason that while this valve consists of a port in a cylinder wall, sealing ring 51A moves over the outside end of the port which is readily rounded and polished and the packing is not damaged.

In constructing the pump,` suiiicient clearance should be provided between the ends of the members 60 and 51, and 59 and 50 respectively, so that lthe upper portion I3 of the inner tube string will be supported, in all operating positions of the valve Si, by the piston 2| in the lift cylinder at the top of the well. This relieves valve seat 44 from the support of the weight of the upper section of inner tube string.

What I claim is:

l. Apparatus for pneumatically pumping liquids from wells which comprises a source of gaseous fluid under pressure, a displacement chamber adapted to be positioned in the liquid in a well, said chamber being provided with a valve seat, a valve movable axially of the seat for venting the chamber of entrapped gas to the well, a second valve seat, a second valve movable axially of the second valve seat for controlling the delivery of gaseous fluid from said source to said chamber, a vertically reciprocable eduction tube in communication with the lower part of said chamber, and extending therefrom to the top of -the well, and means connecting said eduction tube with said valves for operation of the same in accordance with the reciprocation of the eduction tube whereby when the eduction tube is lowered gaseous fluid is admitted to the displacement chamber and when the eduction tube is raised the displacement chamber is vented into the well.

2. Apparatus for pneumatically pumping liquids from deep wells comprising a displacement chamber adaptedlto be positioned in the liquid at the bottom of a well, said chamber being provided with a valve port opening into the well, a vertically reciprocable eduction tube in communication with the displacement chamber and extending to the top of the well, a valve housing provided with a valve port carried by said eduction tube and reciprocable therewith, a source of gaseous fluid under pressure and tubular closure means for said ports, said closure means being in valvular, interlocking engagement with the valve housing through the port in the housing for reciprocation with the eduction tube and being axially movable with respect to each of said ports, said closure means in one position connecting the source of gaseous fluid with the displacement chamber through the valve housing and in a second position venting the displacement chamber to the well.

3. Apparatus for pneumatically pumping liquids from wells comprising a displacement charnber adapted to be positioned in the liquid in a well, said chamber being provided with a valve seat, a vertically reciprocable eduction tube in communication with the lower .part of said chamber and extending therefrom to the top of the well, a valve housing provided with a valve seat carried by said eduction tube and reciprocable therewith, a source of gaseous fluid under pressure, means for connecting the valve housing with the displacement chamber for passage of gaseous fluid from the housing into said chamber, and valve means for the seats axially movable with respect to the seats, said valve means being supported in lowermost position in the well by engagement with the seat on the displacement .chamber and being supported in raised position by engagement with the seat on said valve housing.

4. In a pneumatically operated well pump, a pump casing adapted to be positioned in a well and provided with a liquid inlet at the bottom and means for introducing pressure gas at the top and an intermediate vent, a valve seat in the casing below the vent dening therebelow a lower liquid receiving chamber, packing means in the casing above the vent defining an intermediate gas exhaust chamber therebelow and an upper gas inlet chamber thereabove, a hollow stem double-ended reciprocable valve normally seated on the valveseat and extending through the packing means, a vertically reciprocable eduction pipe extending into the liquid receiving chamber, and valve seat closure means in fixed relation to the pipe, to engage the upper end of the valve on the upstroke of the pump whereby to lift the valve off the lower seat.

v5. A pumpforpneumatically lifting liquids in successive slugs comprising a source of gaseous pressure fluid, a displacement chamber adapted to be positioned in the liquid in a well, said chamber being provided with a valve seat and an axially movable valve for the seat for venting the chamber of entrapped gas into the well, a second valve seat and axially movable valve for the seat for controlling the delivery of gaseous fluid from said source to said chamber, a vertically reciprocable eduction tube in communication with the lower part of said chamber and extending therefrom to the top of the well, said tube having upper and lower sections, valve coupling means joining adjacent ends of said sections adapted to control the delivery of gaseous pressure uid from said source to said tube, and means connecting the lower section of said tube with said axially movable valves for operating the same in accordance with the reciprocation of the lower section of the eduction tube whereby when the eduction tube is lowered gaseous pressure fluid is admitted to the displacement chamber and when the eduction tube is raised the displacement chamber is vented to the well and gaseous pressure fluid from said source is admitted into thc eduction tube at the valve coupling means.

6. A pump for pneumatically lifting liquids comprising a pump casing adapted to be positioned in a well and provided with a liquid inlet at the bottom, means for introducing pressure gas at the top and an intermediate vent, a valve seat in the casing below the vent defining therebelow a liquid receiving chamber, packing means in the casing above the vent defining an intermediate gas exhaust chamber therebelow and an upper gas inlet chamber thereabove, a reciprocable hollow valve stem extending through the packing means and provided with upper and lower valves disposed, respectively, above and below the packing means, said lower valve being normally seated on the valve seat, a vertically reciprocable eduction pipe extending through the hollow stem and communicating with the liquid receiving chamber near the bottom thereof and, annular valve seat closure means in fixed relation to the pipe for engaging the upper valve on the up stroke of the pipe whereby to lift the lower valve oi its seat.

7. The subject matter of claim 6 wherein valve means actuated by reciprocation of the eduction pipe is provided in the gas inlet chamber for controlling the delivery of gas directly into the pipe, and downwardly closing check valve means is provided in the pipe immediately below said valve means.

8. The subject matter of claim 1 wherein the lower end of the displacement chamber is closed by means of a piston connected to the rstnamed valve whereby fluid pressure in the chamber tending to open the valve during displacement of liquid from the chamber is opposed by chamber tending to open said reciprocable valve during expulsion of liquid from the chamber is opposed by the pressure of the fluid in the chamber upon the check valve and piston.

10. In a pump for pneumatically lifting liquids, including a displacement chamber, an eduction tube extending into the chamber and reciprocable relative thereto and means for applying gaseous fluid under pressure to the chamber for 10 forcing liquid out of the chamber through said tube, the improvement which comprises means responsive to the pressure of the fluid in the chamber and connected to the eduction tube for opposing the force resulting from the pressure of 15 the liquid in the chamber which tends to force the eduction tube from the chamber.

l1. In a pump for pneumatically lifting liquids including a displacement chamber and means for admitting gaseous fluid under pressure to`the chamber for expelling liquid therefrom, the improvement which comprises a valve arranged to Aopen outwardly of the chamber for venting the chamber of entrapped gas and means in the chamber connected to said valve and movable in response to the pressure of the fluid in the chamber in a direction opposite to the direction 0f opening of the valve for opposing opening of the valve during displacement of liquid from the chamber.

12. The subject matter of claim 1 wherein the displacement chamber is provided with a cylindrical extension, a piston reciprocable in said extension and subject to the pressure of the uid in said chamber and means connecting said pis- 35 ton to said first named valve.

ROY L. CHENAULT. 

